Hot-air furnace



Dec. 7 1926. 1,609,788

0. W. ANDERSON HOT AIR FURNACE Filed June 19; 1926 Patented Dec. 7, 1926. I UNITED STATES PATENT ()FFICE.

OSCAR ANDERSON, F IRON MOUNTAIN, MICHIGAN.

- HOT-AIR FURNACE.

Application filed June 19, 1928. Serial No. 117,060.

My invention relates to furnaces and par- Leading from a point 11 adjacent the centicularly to hot air furnaces such as are tor of the combustion chamber is a smoke employed for heating dwellings and other eduction pipe 12 which passes downwardly buildings. The object of my invention is from the point 11, through the side of the I to provide a furnace of the character meninner casing 5, preferably just above the tioned of such construction and arrangement fire pot 3, and then downwardly, where it of parts as to insure a substantially comcommunicates at 13 with a smoke pipe 1 1 plete combustion of the fuel, thereby obleading to the flue. The bottom end of the taining a maximum amount of heat from a smoke eduction pipe 12 passes downwardly in given amount of fuel. A further object of below the point of communication with the my invention is to provide a device of the smoke pipe, forming a soot chamber 15 class mentioned which will emit but little, if which is provided with a clean-out door 16. any smoke from the flue. Other objects will Leading from the ash pit 4; is an air pipe appear hereinafter. 17 which passes directly upwardly into the With these objects in view my invention combustion chamber 6 and terminates at 18, consists generally in providing a hot air at the top of the dome 7 and adjacent the furnace with a combustion chamber termicenter thereof. It should be noted that the nating at its upper end in an imperforate pipe 17 has no horizontal, or substantially dome, arranging the flue or smoke pipe so as horizontal parts, and therefore does not to terminate a considerable distance below form any air pockets and that by being arthe top of the dome, and providing means for ranged within the combustion chamber 6 injecting air into the upper portion of the above the fire pot 3,-the air passing upwarddome so as to supply oxygen to the smoke ly therethrough will be highly heated before and gases accumulated in the dome to insure being injected into the dome 7. It will be 39 a substantially complete combustion thereof. noted that the end 18 of the pipe is consid My invention further consists in arranging erably above the inlet end 11 of the smoke the air admission means so as to thoroughly eduction pipe 12. heat the air therein before injecting the air In operation, the products of the combusinto the dome, and of such construction and tion of the fuel in the fire pot 3, consisting arrangement as to avoid pocketing the air, of smoke and gases, pass upwardly into the p and thereby insuring a constant and steady dome 7. These products of combustion are supply of fresh heated air. in a hightly heated state. Air will pass My invention consists in various details freely up the pipe 17 and in so passing will of construction and arran ements of parts be highly heated and injected into the :56 all as will be fully describet hereinafter and trapped smoke and uses in the dome 7, particularly pointed out in the claims. thereby supplying sufficient oxygen for their My invention will be more readily undercomplete combustion. In this manner a maxstood by reference to the accompanying imum amount of heat is obtained from a drawings forming a part of this application. given amount of fuel, and furthermore, the 40 The figure is a vertical section of a fursmoke is substantially completely burned, nace embodying my invention, parts being thereby allowing little or no smoke to pass illustrated in elevation. into the flue. It is also obvious that my in- Referring now to the drawings, 1 indicates vention may be applied to any of the orthe outer casing from the upper end of which dinary hot air furnaces in general use. 45 extends the sleeves 2 for connectingthe usual I claim heat pipes. 3 indicates the fire pot and 4. 1. In a hot air furnace, a fire pot and a the ash pit. Arranged within the casing 1 combustion chamber terminating in an imand spaced therefrom is an inner casing 5 perforate dome, means for injecting air into forming the combustion chamber 6 and terthe upper end of said dome, a smoke educ- 50 n'iinating at its upper end in an imperforate tion pipe leading from said combustion dome 7 8 indicates the feed door, 9 the door chamber below said dome and extending to the ash pit and 10 the draft door. These downwardly on the outside of said fire pot parts with the exception of the imperforate and below the same and a smoke pipe condome 7 are common to furnaces of this class nected with said eduction pipe below the and may be of any ordinary or preferred level of said fire pot, substantially as deconstruction. scribed.

2. In a hot air furnace, a fire pot and a combustion chamber terminating in an imperforate dome, means for injecting air into the upper end of said dome, a smoke eduction pipe leading from said combustion chamber below said dome and extending downwardly 011 the outside of said fire pot and below the same, a smoke pipe connected to said eduction pipe adjacent the lower end thereof, said eduction pipe being extended 10 below the point of connection With the smoke pipe and forming a soot chamber and a clean-out door for said soot chamber, sub stantially as described.

In testimony whereof I have signed my 15 name to this specification.

OSCAR \V. ANDERSON. 

